全麻唤醒和术中电刺激在脑功能区病灶性癫痫手术中的应用

目的 探讨全麻唤醒和术中电刺激在脑功能区病灶性癫痫手术中的应用及意义.方法 对11例涉及脑功能区病灶性癫痫患者术前行MRI和头皮视频脑电图检查,其中6例行fMRI检查.全麻下手术,其中7例行食道咽腔导管插管全麻唤醒.术中皮层脑电图定位痫样放电皮层,皮层电刺激定位皮质功能区,根据病灶、致痫皮层和皮层功能区关系选择相应手术方式,在切除病灶时作皮层电刺激以保护皮质下功能传导束.结果 10例病灶全切除,1例次全切除.术后2例暂时性偏瘫.随访6～24月,患者无神经功能障碍,Kamofsky评分平均100分,使用1种抗癫痫药物,癫痫控制满意.结论 食道咽腔导管插管全麻唤醒屉一种安全、简便的麻醉唤醒方法;术中电刺激监测能够最大限度切除病灶,妥善处理致痫皮层,有效保护脑功能区,改善患者的生活质量.     

脑功能磁共振成像在神经外科中的应用

功能磁共振成像(fMRI)为神经外科治疗脑功能区及邻近部位的病变,切除解剖结构改变不明显的癫癎灶提供了新的无创成像工具.它可用于术前计划的制定,并对手术效果进行预测;术中利用fMRI能在解剖上对功能区进行准确定位,明显提高病灶切除率,同时也可最大程度地保留运动功能;术后应用fMRI可显示病变切除后的手术损伤程度、功能区的残留范围和对侧功能区的代偿情况,并可推测病人的预后状况.本文就fMRI技术在神经外科术前、术中、术后的应用进行综述.     

累及Broca区低级别胶质瘤的BOLD—fMRI及语言功能区的可塑性研究（附15例分析）

目的探讨Bold—fMRI在功能区低级别胶质瘤中的应用及语言功能区的可塑性。方法对15例低级别胶质瘤及14例正常人行fMRI检查并作体素分析。病人在功能影像、术中电刺激指导下进行手术,结合语盲测评、影像评估及Karnofsky功能状态评分（KPS）等进行随访。结果病人较正常人半球激活指数（HAI）低,提示语言功能区重塑。肿瘤全切除11例,近全切除4例。术后短期内有不同程度失语7例,术后3个月均得以恢复。术后KPS评分较术前提高。结论Broca区低级别胶质瘤病人术前、术后语言功能区具有可塑性;应用术前功能影像及术中电刺激指导手术治疗,可提高肿瘤的切除程度,同时亦可保护语言功能。     

术中全麻唤醒下定位切除脑功能区病变(附5例报告)

目的 初步探讨全麻唤醒状态下定位切除脑功能区病变的方法，为深入研究脑功能区微创手术提供经验。方法 对5例脑功能区脑内占位病变病人进行喉罩插管、全麻下神经导航解剖定位开颅，术中麻醉唤醒，在清醒状态下，通过皮质诱发电位及皮质电刺激等方法进行脑功能区定位，在保护脑功能区的前题下切除脑内病变后再在全麻下关颅。结果 5例病人均顺利经过喉罩插管下全麻一术中唤醒一再全麻，其中3例安全经历术中拔管和再插管。唤醒后脑功能区经采用神经电生理技术得到定位，脑内病变得到最大程度切除，无术后神经功能障碍发生，术前神经功能障碍均明显恢复，其中3例功能完全恢复正常。无手术并发症，病人术后无痛苦回忆。1例术前频繁发作癫痫唤醒后出现癫痫发作。结论 全麻唤醒状态下进行皮质电刺激及皮质诱发电位定位脑功能区手术有助于最大程度地切除脑功能区病灶，提高病人术后生存质量。     

脑功能区胶质瘤手术中的新技术

目的探讨切除脑功能区胶质瘤手术新技术与方法。方法48例脑功能区胶质瘤经术前常规MRI、弥散张力成像(DTI)和fMRI定位大脑皮层功能区及功能投射纤维束,以神经导航为前导,在术中全麻唤醒状态下,通过术中B超定位脑内病灶,皮层体感诱发电位(Co-SEP)及皮层直接电刺激术(Co-ST)脑功能区定位,并在清醒状态下切除病变。术后随访时间3-42个月。结果16例Co-SEP确定中央沟,42例Co-ST明确运动区,16例Co-ST确定语言运动区;肿瘤全切35例,次全切除9例,部分切除4例。术后1个月神经症状好转44例,术后出现暂时性局部神经症状36例;长期局部神经症状加重4例,无手术死亡。全部患者无手术痛苦回忆。结论术中全麻唤醒、皮层-皮层下电刺激术和脑超声技术是切除功能区胶质瘤必备的三项基本技术;术前fMRI与DTI为脑功能区手术提供十分重要信息,神经功能导航为术中功能区定位提供重要前导,综合使用这些现代技术能够在术中明确脑功能区与肿瘤切除范围的关系,做到最大限度地切除脑功能区病变和保护脑功能。     

汉-英双语言脑功能区外科手术定位的探讨

目的探讨中国人汉-英语的脑功能区定位及手术方法。方法对1例广东籍汉语普通话-英语双语言脑功能区低级别胶质瘤病人，术前通过汉、英语语义、语音和图文实验任务，经功能磁共振（fMRI）定位汉语和英语皮质区．由神经功能导航制定手术计划和定位，术中采用超声探测肿瘤，全麻唤醒下双语定位监测功能区，行显微手术切除病变。结果fMRI检出汉语激活区在肿瘤的前下外部，即额中下回后部，英语激活区则位于近肿瘤的额上中回后部。切除肿瘤过程中英语较汉语出现明显障碍征象。肿瘤获次全切除，术后出现短暂辅助运动区（SMA）综合征，英语运动性失语于术后1周内恢复；术后3个月，fMRI显示英语激活区重塑位移。术后8个月随访，病人恢复正常生活和工作，术前癫痫症状消失。结论①采用双语方式进行fMRI扫描定位、神经导航功能区定位和术中清醒状态下双语监测，使双语言脑功能区病变病人的手术治疗成为可能。②在保留母语功能的前提下，对第2语言区病变做到最大限度切除后，其语言功能仍可能得到恢复。     

术中皮质体感诱发电位与电刺激术定位脑功能区

目的探讨脑功能区手术中利用脑皮质体感诱发电位(SEP)及直接皮质电刺激定位脑功能区的方法及意义。方法对10例脑功能区病变病人在唤醒麻醉下进行手术，利用皮质SEP及皮质直接电刺激定位感觉区、运动区及语占区，住保护脑功能区的前提下，手术切除病变。结果7例病人利用SEP及皮质电刺激确定出运动感觉区，其中4例利用SEP位相倒置确定出中央沟，3例病变位于左侧额颞叶的病人通过皮质直接电刺激确定出语言区?术后功能均较术前明显好转。结论术中SEP及直接皮质电刺激可准确、实时确定脑功能区，最大程度地保护功能，切除病变。     

涉及中央区难治性癫(癎)的外科治疗

目的 探讨涉及中央区难治性癫(癎)的手术治疗.方法 3例患者术前除常规致癫(癎)灶评估外,还应用fMRI作皮质功能区定位.术中通过皮层EEG(ECoG)对致癫(癎)灶定位,通过皮层诱发电位(SEP)及皮质电刺激定位脑功能区,对位于功能区以外的致疒间灶行切除性手术,功能区内的致疒间灶行软脑膜下横行纤维切断术.结果 术后无神经功能障碍,术后3月,2例病人无癫(癎)发作,1例偶有部分性发作;术后8月,1例无发作,1例偶有部分性发作,1例减少75%发作. 结论术前功能区评估、术中电生理监测有助于保护皮质重要功能和提高手术癫(癎)控制率.     

涉及中央区难治性癫痫的外科治疗

目的探讨涉及中央区难治性癫痫的手术治疗。方法3例患者术前除常规致痫灶评估外,还应用fMRI作皮质功能区定位。术中通过皮层EEG（ECoG）对致痫灶定位,通过皮层诱发电位（SEP）及皮质电刺激定位脑功能区,对位于功能区以外的致痫灶行切除性手术,功能区内的致痫灶行软脑膜下横行纤维切断术。结果术后无神经功能障碍,术后3月,2例病人无癫痫发作,1例偶有部分性发作;术后8月,1例无发作,1例偶有部分性发作,1例减少75%发作。结论术前功能区评估、术中电生理监测有助于保护皮质重要功能和提高手术癫痫控制率。     

核磁共振脑功能成像指导切除脑功能区肿瘤(附6例报告)

目的应用核磁共振脑功能成像(fMRI)定位脑功能区,指导手术切除脑功能区肿瘤。方法对6例右额顶叶区胶质瘤病人术前行复杂手指运动fMRI,激活脑皮质功能区,明确兴奋灶与肿瘤的位置关系,进而确定手术方案。结果额叶切除1例,显微镜下全切2例,次全切2例,右顶叶前半部分切除1例;仅后者出现左侧肢体肌力减弱,且逐渐恢复。余无并发症。结论fMRI可以明确右额顶叶皮质功能区,提示功能区与胶质瘤的位置关系,指导肿瘤的切除范围和程度。     

Contribution of cortical and subcortical electrostimulation in brain glioma surgery: methodological and functional considerations.

The aim of brain glioma surgery is to maximize the quality of resection, while minimizing the risk of sequelae. Due to the frequent location of gliomas in "eloquent areas" and because of major interindividual anatomofunctional variability, the cortical functional organization, effective connectivity and potential for plasticity must be studied for each patient individually. Consequently, in addition to preoperative functional neuroimaging, intraoperative electrostimulation (IES) can be used, under general anesthesia for motor mapping or on awake patient for language and cognitive mapping. This is an easy, accurate, reliable, and safe technique of detection of both cortical and subcortical functionally essential structures. Thus, IES enables: (i) to study the individual cortical functional organization before any resection; (ii) to understand the pathophysiology of areas involved by gliomas; (iii) to map the subcortical structures along the resection, allowing a study of the anatomofunctional connectivity; (iv) to analyze the mechanisms of on-line short-term plasticity, using repeated IES; (v) to tailor the resection according to individual cortico-subcortical functional boundaries, enabling to optimize the benefit:risk ratio of surgery. Moreover, IES can be combined with perioperative functional neuroimaging, before and after surgery, to validate these noninvasive techniques and to better understand the short-term and long-term plasticity mechanisms based on functional cortical reshaping and connectivity changes. Such individual knowledge allows planning multiple-stages surgery. In conclusion, IES enables to increase the impact of surgery on the natural history of gliomas, to preserve the quality of life, and to better understand the dynamic functional anatomy of the brain.     

唤醒麻醉和术中功能定位切除语言区胶质瘤

目的探讨语言功能区胶质瘤的手术策略。方法回顾性分析手术治疗30例语言功能区胶质瘤。在唤醒麻醉下应用术中直接皮质电刺激确定语言区,根据功能边界切除肿瘤。评价患者的功能结果及切除程度。结果术中语言功能区监测成功20例;未监测到4例;因麻醉或术中高颅压不能进行监测6例。随访3个月,3例患者存在中度语言功能障碍。全切14例,近全切12例,大部切除4例。结论术中皮质电刺激确定语言功能区准确、安全、可靠。唤醒麻醉下进行术中皮质电刺激结合术前神经功能影像技术,确定切除肿瘤的功能边界,能够最大程度切除肿瘤,同时保护正常的语言功能,使术后语言障碍的风险降到最低。     

Controversy in the management of WHO grade II gliomas in eloquent brain areas: recent literature review

Recent studies have shown that diffuse grade II gliomas (GGII) located in eloquent brain areas represent over 80% of all GGII. The optimal management of these tumours is still controversial. It has long been considered that surgery is not an option for GGII within eloquent areas, due to the high risk of inducing postoperative sequelae in patients with normal neurological explorations. However, the safety of these surgeries has significantly improved in recent years due to the rapid development of techniques enabling a precise mapping of brain functions. Noninvasive functional neuroimaging techniques have been recently developed, enabling cortical mapping of the entire brain prior to surgical procedures. Such precise data provide a preoperative estimation of the location of eloquent areas in relation to the tumour, which is essential for surgical planning and preoperative assessment of morbidity for various surgical approaches. The intraoperative electrical stimulation (IES) mapping technique consists in the application of a bipolar electrode on the brain tissue, enabling an accurate location of brain functions. This provides unique assistance in GGII resection, as it generates a discrete and transient "virtual" lesion within the eloquent tissue. Tumour removal is then tailored according to functional boundaries in order to optimise the quality of resection and to minimise the risk of postoperative sequelae, preserving quality of life. For patients with a GGII in an eloquent area, the possibility of an early resection should be evaluated by a multidisciplinary neuro-oncology team specialising in the management of such tumours.     

Brain surface reformatted imaging (BSRI) in surgical planning for resections around eloquent cortex

Background Resective surgeries around eloquent areas challenge neurosurgeons and neuroimaging professionals due to difficulties to find anatomic references during surgery. Advances in magnetic resonance (MR) may prevent such deficits and provide information for accurate surgical planning. However, most of these techniques are expensive and not feasible in most centers. Using brain surface reformatted imaging (BSRI) of 3-D MR images, we sought to obtain data for surgical planning in patients with lesions around the motor cortex.Methods Thirteen patients with lesions around the eloquent areas and considered for resective surgery were evaluated. Patients had different ages with tumors and malformative lesions. They were scanned in a 1.5-T Siemens magnet with volumetric sequence after injection of Gadolinium. Postprocessing was done in an auxiliary console using MRI station software. We performed reformatting as described by Hattingen et al. [J Neurosurg 102:302–310, 2005] and used fixed skull and vascular structures as anatomical references. Distances to the reference points were measured to allow surgical planning and locate sites for cortical stimulation. Patients were also studied by blood-oxygen-level-dependent functional magnetic resonance imaging to locate the hand area before the surgical procedure. All patients had cortical stimulation during the resective procedure or chronic electrode stimulation before surgery.Results There was concordance between data from functional and structural data. In one case, partial resection was performed due to the high risk of severe deficits. Even in this case, there were clinical improvements and no additional deficits were observed.Conclusion BSRI may be a useful tool for surgical planning around eloquent areas. It can reduce surgical time and morbidity and showed correlation with functional studies. Added to this is the low cost and feasibility in most centers that have standard MR scanners with Multiplanar Reformatting software.     

The present and future of cerebral tumor surgery in children

Cerebral hemisphere tumors are less common than posterior fossa tumors in children, but are still important among childhood tumors. At the present time, many are low grade and can be treated satisfactorily with modern surgical techniques. These techniques include image-guided surgery in the conventional operating room, brain mapping, and surgery in the intraoperative MRI. Technical sophistication is the chief characteristic of present approaches to cerebral cortical tumors. In the future, surgery for these tumors will require both technical and biological sophistication. Malignant cerebral tumors are invasive and heterogeneous and require new understandings of biology to develop effective treatments. These biological understandings will be added to sophisticated surgical techniques for surgical resection, perhaps with local delivery methods.     

Intraoperative cortico-subcortical stimulations in surgery of low-grade gliomas

In order to increase the impact of surgery on the natural history of low-grade glioma, resection should be of maximum importance. Nevertheless, since low-grade gliomas are frequently located in eloquent structures, function needs to be preserved. Therefore, studying the functional organization of the brain is mandatory for each patient due to the inter-individual anatomofunctional variability, increased in tumors due to cerebral plasticity. This strategy enables performance of a resection according to functional boundaries. However, preoperative neurofunctional imaging only allows the study of the gray matter. Consequently, since low-grade glioma invades cortical and subcortical structures and shows an infiltrative progression along the fibers, the goal of this review is to focus on the techniques able to map both cortical and subcortical regions. In addition to diffusion tensor imaging, which gives only anatomical information and still needs to be validated, intraoperative direct cortico-subcortical electrostimulation is the sole current method allowing a reliable study of the individual anatomofunctional connectivity, concerning sensorimotor, language and other cognitive functions. Its actual contribution is detailed, both in clinical issues, especially the improvement of the benefit/risk ratio of low-grade glioma resection, and in fundamental applications--namely, a new door to the connectionism and cerebral plasticity.     

Motor and Sensory Mapping of the Frontal and Occipital Lobes

Summary: In patients with intractable epilepsy, surgical resections are performed with the primary goal of improving seizure control. The risk is that the resections may also remove tissues crucial for normal activities. The goal of surgical planning is therefore to determine as accurately as possible the regions of seizure onset and the regions controlling important functions, so that one can determine what to remove and what to leave in place. Clinical functional localization has been performed using cortical stimulation for over half a century, using both intraoperative and extraoperative methods. Signal averaging also has been widely used. More recently, techniques based on analysis of EEG in the frequency domain have shown promise. The methods appear to accurately indicate the function of the region assessed but do not necessarily predict functional consequences of resection. We review these methods, their indications, and the results obtained by their use.     

Optimizing brain tumor resection. Low-field interventional MR imaging

In this article, the authors describe their strategy for intraoperative MR image guidance of tumor resection at low-field (0.2 T) strength. It is their opinion that intraoperative imaging is most useful in assessing the resection of intrinsic, infiltrating brain tumors; boundaries of the tumor cannot be clearly distinguished with the surgeon's eyes, and therefore, this discussion predominantly applies to the surgical resection of gliomas.     

Intraoperative mapping of the cortical areas involved in multiplication and subtraction: an electrostimulation study in a patient with a left parietal glioma

OBJECTIVES: Advances in neuroimaging studies have recently improved the understanding of the functional anatomy of the calculation processes, having in particular underlined the central role of the angular gyrus (AG). In this study, the authors applied this knowledge to the surgical resection of a glioma invading the left AG, by localising and sparing the cortical areas involved in two different components of calculation (multiplication and subtraction), using direct electrical stimulations. METHODS: A calculation mapping was performed in a patient without deficit except a slightly impaired performance for serial arithmetic subtraction, during the resection under local anaesthesia of a left parieto-occipital glioma invading the dominant AG. After somatosensory and language mappings, cortical areas involved in single digit multiplications and subtractions of seven were mapped using the method of electrostimulation, before glioma removal. RESULTS: Distinct sites specifically involved in multiplication or subtraction were detected within the left AG, with a precise spatial distribution and overlapping. All the eloquent (somatosensory, language, and calculation) areas were surgically spared. Postoperatively, the patient had a transient complete deficit for arithmetic subtraction, without either multiplication or language disturbance. The tumour removal was complete. CONCLUSIONS: These findings suggest: firstly, the usefulness of an intraoperative calculation mapping during the removal of a lesion involving the left dominant AG, to avoid permanent postoperative deficit of arithmetic processes while optimising the quality of tumour resection; secondly, the possible existence of a well ordered and dynamic anatomo-functional organisation for different components of calculation within the left AG.     

Functional MRI and intraoperative brain mapping to evaluate brain plasticity in patients with brain tumours and hemiparesis

OBJECTIVE: To support the hypothesis about the potential compensatory role of ipsilateral corticofugal pathways when the contralateral pathways are impaired by brain tumours. METHODS: Retrospective analysis was carried out on the results of functional MRI (fMRI) of a selected group of five paretic patients with Rolandic brain tumours who exhibited an abnormally high ipsilateral/contralateral ratio of activation-that is, movements of the paretic hand activated predominately the ipsilateral cortex. Brain activation was achieved with a flexion extension of the fingers. Statistical parametric activation was obtained using a t test and a threshold of p<0.001. These patients, candidates for tumour resection, also underwent cortical intraoperative stimulation that was correlated to the fMRI spatial data using three dimensional reconstructions of the brain. Three patients also had postoperative control fMRI. RESULTS: The absence of fMRI activation of the primary sensorimotor cortex normally innervating the paretic hand for the threshold chosen, was correlated with completely negative cortical responses of the cortical hand area during the operation. The preoperative fMRI activation of these patients predominantly found in the ipsilateral frontal and primary sensorimotor cortices could be related to the residual ipsilateral hand function. Postoperatively, the fMRI activation returned to more classic patterns of activation, reflecting the consequences of therapy. CONCLUSION: In paretic patients with brain tumours, ipsilateral control could be implicated in the residual hand function, when the normal primary pathways are impaired. The possibility that functional tissue still remains in the peritumorous sensorimotor cortex even when the preoperative fMRI and the cortical intraoperative stimulations are negative, should be taken into account when planning the tumour resection and during the operation.